A multi-tracer approach to study urban air pollution using satellites

Urban air quality is a growing environmental problem and threat to human health, especially in developing countries with limited resources to setup air quality monitoring networks in support of local pollution abatement policies. The burning efficiency is a crucial factor in determining the environmental impact of fuel burning. It is determined by the fuel burning conditions, which are estimated mostly by the technology used for combustion. This, in turn, affects the emission ratio of pollutants, as indicated by the emission factor. The limited knowledge about emission factors contributes significantly to the uncertainty in regional and global emission inventories.Additionally, anthropogenic emissions impact urban photochemistry and atmospheric oxidants such as the hydroxyl radical (OH). OH, plays an important role in atmospheric chemistry as it determines the lifespan of greenhouse gases (Methane (CH4) and Hydrochlorofluorocarbon (HCFC’s) and air pollutants such as carbon monoxide (CO) and nitrogen oxides (NOx = NO + NO2). The OH abundance is a sensitive indicator, although difficult to measure, of the photochemical regime and the presence of ozone causing photochemical smog.The aim of this thesis is to develop new methods to support the monitoring of air quality in cities around the world using satellite remote sensing. These methods estimate fuel burning efficiency, OH concentrations and the NOx lifetime (